PA4EME

Dutch Amateur Radio Station

Frank Veldhuijsen

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Remote QTH in Meijel, JO21WA

 

Nowadays, working EME can be fustrating due to the raising noiselevel in urban surroundings. Therefore more and more stations are setting up a remote location. As my EME-neighbour Lins, PA3CMC, was suffering the same problem, we decided to build a remote station together. It will be located in Meijel, near the QTH of PA3CMC but outside the village. We call it EME-project 2009. When finished the station will consist of 8 x 32 element XPOL Yagis. All hardware is already collected...just the needed time to build it up is a problem as both Lins and I are working on new carreers and new companies. This is taking a lot of time and efforts for both of us. Lins has build up a temporary antenna of 4 x 19 elements LLY Yagis and is enjoing the very low noiselevel at the remote site.

Scroll down to see more pictures from the EME-project 2009

Text Box: General overview of the remote site. It is used as a storage for soil, grit and some containers for the company of PA3CMC (Martens Milieu).

An old shed is available but in bad condition. However it keeps us out of the rain as long as the mobile shack is not in place yet.

A group of 4x12 elements M2 was used to see if the remote site was free of noise. A test proved that the site has a low noise level and the 144 MHz band is free of birdies.

For an eight Yagi group a decent rotor is necessary. From ON4AOI a Rhode & Schwarz rotator was purchased. Most hardware in good shape but the motor needs work.

It is real heavy duty and has been used for rotating a big commercial logperiodic anten-na.

Job done...after a 1.5 hours drive safely stored in the workshop. The size can derived from the size of the Europallet (80x120 cm).

To control the antenna an OE5JFL antenna-controller was build. This controller tracks the moon independent from a computer.

Inside view of the controller. The hart is formed by a PLCC44 microprocessor from Atmel. It can be accessed through the internet.

A relayboard was designed too to be able to switch the azimuth and elevation motors. Readout is done by absolute encoders at 0.2 degrees accuracy.

The absolute encoders MAB25 and the well writen building manual from Alex, HB9DRI. The design is from Johannes, OE5JFL.

Lins, PA3CMC, brought in his 4x32 XPOL from IoJXX. I did the same so now we have 8 x32 XPOL. Lins decided to build a 4x19 LLY for the timebeing.

The mobile shack. Maybe you like the graffity...we do not so we need to do some paintwork on the outside.

For controlling the station a 4-stage sequencer was build. Indeed...it can be smaller but this will allow easy repairment when needed.

This heavy 4200 Volts, 2 amperes, high voltage powersupply will be taken out of service. It will be for sale very soon.

The GS35b cavity had found a place in the mobile shack. However rugged SSPA have found the way to hamradio. This modified TV amplifier will do vy fine on 144 MHz.

To control the GS35b a triode controller was build as a GM3SEK triodeboard cloon. As the GS35b will not used anymore, this will be for sale soon as well.

The GM3SEK schematic was used to design an own PCB that was manufactured at home. When hooked up the first time it smoked as the K+F and K were switched somewhere during the build (cavity was at remote site).

Picture of the temprary setup of 4x19 ele-ments LLY Yagi (I3DLI design) from Lins, PA3CMC. With no vertical polarisation it sometimes takes more time but still doing very fine.

GS35b cavity. The design looks like UV1US/RX1AS or PA3CSG but the tube has a larger diameter like F1CXX.

Detailed picture of the loadcapacitor of the ampifier. A mica sheet is mounted between the plates to prevent a flash over.

Detailed picture of the tuning capacitor. A mica sheet is mounted between the plates to prevent a flash over. A 50 Ohm line has been made from two copper tubes with the right dimensions. Output connector is 7/16. For testing a N to 7/16 was used as can be seen on the picture. Output is more than 63 dBm.

OZ1PIF has nice PCB for ATF-54143 preamplifiers that are based on the PA3BIY design. NF should be below 0.25 dB

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